Toilet flusher with novel valves and controls

ABSTRACT

A tank-type flusher includes an intake valve, i.e., a fill valve, a diaphragm-operated flush valve, and a pressure control mechanism. The intake valve is connected to an external water source and is constructed to close water flow to a water storage tank at about a predefined water level in the water tank. The diaphragm-operated flush valve is constructed to control a flush valve member between a seated state and an unseated state allowing water discharge from the water tank into a toilet bowl. There is a diaphragm, separating a flush-valve chamber and a pilot chamber, arranged to seal the flush-valve chamber and thereby maintain pressure forcing the flush valve member to the seated state preventing the water discharge from the water storage tank to the toilet bowl. The pressure control mechanism is constructed and arranged, upon actuation, to reduce pressure in the pilot chamber of the diaphragm-operated flush valve to cause deformation of the diaphragm and thereby reduce pressure in the flush-valve chamber causing the water discharge.

[0001] This application claims priority from PCT ApplicationPCT/US01/43273, filed Nov. 20, 2001, which is a continuation-in-part ofU.S. application Ser. No. 09/716,870, entitled “Timed Fluid-Linked FlushController,” filed on Nov. 20, 2000; U.S. application Ser. No.09/761,408, entitled “Flusher Having Consistent Flush-Valve-ClosurePressure,” filed on Jan. 16, 2001; U.S. application Ser. No. 09/761,533,entitled “Supply-Line-Sealed Flush Controller,” filed on Jan. 16, 2001;PCT Application PCT/US01/11384, entitled “Automatic Tank-Type Flusher,”filed on Apr. 6, 2001; and U.S. application Ser. No. 09/957,761 entitled“Push Button For Metered Flow,” filed on Sep. 21, 2001.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention is directed to toilet flushing. It findsparticular, although not exclusive, application in automatic tank-typeflushers.

[0004] 2. Background Information

[0005] The art of toilet flushers is an old and mature one. (We use theterm toilet here in its broad sense, encompassing what are variouslyreferred to as toilets, water closets, urinals, etc.) While manyinnovations and refinements in this art have resulted in a broad rangeof approaches, flush systems can still be divided into two generaltypes. The first is the gravity type, which is used in most Americandomestic applications. The gravity type uses the pressure resulting fromwater stored in a tank to flush the bowl and provide the siphoningaction by which the bowl's contents are drawn from it. The second typeis the pressurized flusher, which uses line pressure more or lessdirectly to perform flushing.

[0006] Some pressure-type flushers are of the tank type. Such flushersemploy pressure tanks to which the main water-inlet conduitcommunicates. Water from the main inlet conduit fills the pressure tankto the point at which air in the tank reaches the main-conduit staticpressure. When the system flushes, the water is driven from the tank ata pressure that is initially equal to that static pressure, withoutreduction by the main conduit's flow resistance. Other pressure-typeflushers use no pressure tank, and the main conduit's flow resistancetherefore reduces the initial flush pressure.

[0007] While flush-mechanism triggering has historically been performedmanually, there is also a long history of interest in automaticoperation. Particularly in the last couple of decades, moreover, thisinterest has resulted in many practical installations that have obtainedthe cleanliness and other benefits that automatic operation affords. Asa consequence, a considerable effort has been expended in providingflush mechanisms that are well adapted to automatic operation. Automaticoperation is well known in pressure-type flushers of the non-tankvariety, but gravity-type flushers and pressurized flushers of the tankvariety have also been adapted to automatic operation.

[0008] European Patent Publication EPO 0 828 103 A1 illustrates atypical gravity arrangement. The flush-valve member is biased to aclosed position, in which it prevents water in the tank from flowing tothe bowl. A piston in the valve members shaft is disposed in a cylinder.A pilot valve controls communication between the main (pressurized)water source and the cylinder. When the toilet is to be flushed, onlythe small amount of energy required for pilot-valve operation isexpended. The resultant opening of the pilot valve admits line pressureinto the cylinder. That pressure exerts a relatively large force againstthe piston and thereby opens the valve against bias-spring force. Pilotvalves have similarly been employed to adapt pressure-type flushers toautomatic operation.

SUMMARY OF THE INVENTION

[0009] According to another aspect, a tank-type flusher includes anintake valve (i.e., a fill valve), a diaphragm-operated flush valve, anda pressure control mechanism. The intake valve is connected to anexternal water source and is constructed to close water flow to a waterstorage tank at about a predefined water level in the water tank. Thediaphragm-operated flush valve is constructed to control a flush valvemember between a seated state and an unseated state allowing waterdischarge from the water tank into a toilet bowl. There is a diaphragm,separating a flush-valve chamber and a pilot chamber, arranged to sealthe flush-valve chamber and thereby maintain pressure forcing the flushvalve member to the seated state preventing the water discharge from thewater storage tank to the toilet bowl. The pressure control mechanism isconstructed and arranged, upon actuation, to reduce pressure in thepilot chamber of the diaphragm-operated flush valve to cause deformationof the diaphragm and thereby reduce pressure in the flush-valve chambercausing the water discharge.

[0010] Preferred embodiments of this aspect include one or more of thefollowing features: The intake valve includes a float constructed andarranged without any fixed coupling to any valve member. The intakevalve includes a float that freely floats within a float cage. Theintake valve includes a float arranged to float within a float cage andto block a relief orifice at the predefined water level.

[0011] The pressure control mechanism is controlled by a solenoid. Theflush valve member is constructed to move linearly within a flush valvehousing. The flush-valve chamber is arranged to receive water pressurefrom the external source and being arranged to prevent the waterdischarge utilizing at least a portion of the water pressure.

[0012] According to another aspect, a tank-type flusher includes anintake valve (i.e., a fill valve), and a diaphragm-operated flush valve.The intake valve is constructed to close water flow from an externalwater source to a water storage tank when there is a predefined waterlevel in the water tank. The intake valve includes a float constructedand arranged to freely float within a float cage. The diaphragm-operatedflush valve includes a flush-valve chamber, wherein thediaphragm-operated flush valve is constructed to open upon actuation todischarge water into a toilet bowl from the water tank.

[0013] According to yet another aspect, a tank-type flusher includes anintake valve, and a diaphragm-operated flush valve. The intake valve isconnected to an external water source and is constructed to close waterflow to a water storage tank at about a predefined water level in thewater tank. The flush valve is constructed to control position of aflush valve member movable between a seated state and an unseated stateallowing water discharge from the water tank into a toilet bowl, whereinthe flush valve member is biased to the unseated state by a bias memberand is forced to the seated state by at least a portion of waterpressure from the external source.

[0014] Preferred embodiments of this aspect include one or more of thefollowing features: The intake valve and the flush valve are locatedwithin a single housing. The flush-valve chamber is arranged to receivea water pressure from the external source and is arranged to prevent thewater discharge utilizing at least a portion of the water pressure.

[0015] The diaphragm-operated flush valve may be controlled by asolenoid. The water tank may be an exposed water tank or a concealedwater tank located behind a wall. The intake valve enables a variablewater level in the tank.

[0016] The tank-type flusher may include a vacuum breaker arranged toprevent transfer of water from the tank to a water supply.

[0017] The tank-type flusher may includes a manual actuator constructedand arranged to actuate the flush valve. The manual actuator may be apush button actuator. The push button actuator is constructed to actuatethe flush valve enabling a dual water volume flush. The push buttonactuator is constructed to actuate hydraulically the flush valve.

[0018] The tank-type flusher may include an automatic actuatorconstructed and arranged to actuate the flush valve. The automaticactuator is constructed to be triggered by a sensor. The sensor mayregister presence of an object or movement of an object. The sensor maybe an optical sensor. The automatic actuator may be constructed toactuate the flush valve enabling a dual water volume flush. Theautomatic actuator may be located outside of the water tank and isconstructed to actuate hydraulically the flush valve.

[0019] The tank-type flusher may include a check valve arranged toreduce variation of closing pressure depending on water line pressure.The tank-type flusher may include a pressure compensated flow regulator.The tank-type flusher may includes a viper seal co-operatively arrangedwith the flush valve to prevent water leaking into the toilet bowl. Thetank-type flusher may include a vent for controlling odor.

[0020] We have invented novel gravity-type and pressure-type flushmechanisms. In the case of the gravity-type flush valve, we haverecognized that operation can be made more repeatable by simplyemploying a configuration that is the reverse of the one described inthe above-mentioned European patent publication. Specifically, we biasour flush valve to its unseated state, in which it permits flow from thetank to the bowl, and we use line pressure to hold the flush valve shutrather than to open it. We have recognized that this approach makes itvery simple to have a repeatable valve-opening profile. Also, high linepressure actually aids in preventing leakage through the flush valve,rather than tending to reduce the effectiveness of the flush-valve seal.Since the toilet's suction generation is principally dependent on thatprofile, and since our approach makes the bias mechanism essentially thesole determinant of that profile, our approach enables this aspect offlush operation to be largely independent of line pressure.

[0021] We have also recognized that pressure-type flush systems adaptedfor automatic operation can be simplified by providing a pressure-reliefpassage that extends through the flush-valve member itself.Specifically, part or the entire valve member is disposed in a pressurechamber, into which line pressure is admitted. This pressure overcomes abias force and holds the valve member in its seated position, in whichit prevents flow from the pressurized-liquid source into the bowl. Toopen the flush valve, it is necessary to relieve the pressure in thepressure chamber by venting it into some unpressurized space. Ratherthan follow the conventional approach of providing an additionalpressure-relief exit from the flush mechanism, we use the flush outletfor pressure relief by providing a pressure-relief conduit that extendsfrom the pressure chamber through the flush-valve member itself. Apressure-relief mechanism ordinarily prevents flow through thispressure-relief conduit, but it permits such flow when the toilet is tobe flushed.

[0022] In both pressure- and gravity-type systems, much of the mechanismemployed to operate the flush valve is typically local to the wetregion. That is, it is inside the pressure vessel in the case of apressure-type system, and it is in the tank below the high-water line incase of a gravity-type system. For automatic operation, though, at leastsome part, such as a lens used as part of an object sensor to collectlight reflected from the object, is disposed at a remote location. Sothere is some communication between the local and remote regions. Thiscommunication may be totally hydraulic, wherein a pressure-relief lineextends from the local region to a remote region outside the pressurevessel or outside the part of the tank interior. A remote valve controlsa pressure-relief line for controlling the flush valve's operation. Inthis embodiment, there is no need for a sealed enclosure for theelectrical components.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023]FIG. 1 is a sectional view of a toilet tank illustrating its floatand gravity-type flush valves.

[0024]FIG. 1A is a more-detailed cross section of the gravity-type flushvalve in its closed state.

[0025]FIG. 1B is a similar view of the gravity-type flush valve, but inits open state.

[0026]FIG. 1C is a cross-sectional view depicting FIG. 1's gravity-typeflush valve in more detail.

[0027]FIG. 1D is a cross-sectional view of an alternative flush-valvearrangement, in which solenoid-control circuitry is located remotelyfrom a solenoid located in the flush-valve assembly.

[0028]FIG. 2 is a cross-sectional view that illustrates an embodiment inwhich the float- and flush-valve assemblies share common elements.

[0029]FIG. 2A is a cross-sectional view of another embodiment, one inwhich the solenoid as well as the solenoid-control circuitry is locatedremotely from the flush-valve assembly.

[0030]FIG. 3 is a cross-sectional view of a pressure-type embodiment.

[0031]FIG. 3A is a more-detailed cross-sectional view of a pilot-valvefor the pressure type embodiment.

[0032]FIG. 4 is a sectional view of a toilet tank illustrating its floatand gravity-type flush valves.

[0033]FIG. 4A is a more-detailed cross section of the gravity-flushvalve in its closed state.

[0034]FIG. 4B is a similar view of the gravity-type flush valve, but inits open state.

[0035]FIG. 5 is a cross-sectional view of the push-button valve of FIG.4.

[0036]FIG. 5A is a cross-sectional view taken at line 5A-5A in FIG. 5.

[0037]FIG. 6 is a sectional view of the toilet tank illustrating itsfloat and gravity-type flush valves.

[0038]FIG. 6A is a more-detailed cross section of the flush-valvemechanism.

[0039]FIG. 6B is a cross-sectional view of a remote actuator valve andpush button.

[0040]FIG. 6C is a top isometric view of one of the push-button membersin the push-button assembly of FIG. 3.

[0041]FIG. 6D is an isometric view of the button frame in FIG. 3'spush-button assembly.

[0042]FIG. 6E is an isometric view of another button member from thepush-button assembly of FIG. 6B

[0043]FIG. 7 includes FIGS. 7A and 7B wherein FIG. 7A is a more detailedcross sectional view of FIG. 6's float-valve assembly and FIG. 7B is across-sectional view of the flush-valve assembly showing a fill tube anda flow diverter.

[0044]FIG. 8 is a cross-section of a valve that employs the presentinvention's teachings.

[0045]FIG. 8A is an isometric view of a stop member employed in analternative embodiment of the present invention.

[0046]FIG. 8B is a plan view of the FIG. 8A embodiment with partsremoved.

[0047]FIG. 8C is an isometric view of the inner button member employedin the FIG. 8A embodiment.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0048] Referring to FIG. 1, a gravity-type flush mechanism includes afill valve mechanism 5 and a flush-valve mechanism 10 located in atoilet tank 16. Toilet tank 16 is an exposed tank traditionally used inthe US, or a concealed tank frequently used in the EU countries. FIG. 1Ashows flush-valve mechanism 10 in a closed state wherein flush-valvemember 12 is seated in a flush-valve seat 14 formed in the bottom oftoilet tank 16. In that seated position, the valve member 12 preventswater from the tank 16 that has entered through flush ports 18 in aflush-valve housing 20 from flowing through a flush outlet 21 and aflush conduit 22 to a toilet.

[0049] The flush mechanism includes a bias spring 24, which exerts aforce that tends to urge flush-valve member 12 off its seat 14. That is,flush-valve member 12 is biased to an unsealed state but remains seatedbetween flushes due to water line pressure. This pressure that normallyprevails in a flush-valve (or piston) chamber 25 because of itscommunication with a (pressurized-) water source conduit 26. Theflush-valve housing 20's cap 27 provides this chamber, and theflush-valve member is slidable within a cylinder 28 that the cap forms.

[0050] Referring to FIGS. 1A and 1B, operation of flush valve mechanism10 is controlled by pressure in chamber 25 using a pilot valve diaphragm30. The valve member's seal ring 29 cooperates with diaphragm 30 toprevent escape of the pressurized water from piston chamber 25 through apressure-relief outlet 31 in chamber 25's narrowed passage portion 32.Diaphragm 30 is resiliently deformable so pressure within passage 32tends to lift it from engagement with a pilot-valve seat 34 and asimilar pressure within a pilot chamber 36 acts on diaphragm 30 in theopposite direction over a greater area. There is a small orifice 38through which a pilot-valve pin 40 extends, and orifice 38 permits waterto bleed into it (through a relatively high flow resistance) to equalizethe pressure. Due to a greater surface area of diaphragm 30 in chamber36 there is a net force that keeps diaphragm 30 seated at seat 34.

[0051] To cause the system to flush, a solenoid 42 withdraws a secondpilot-valve member 44 from a seat to enable flow through a passage 46that leads from chamber 36 to a further passage 48 that leads to anoutlet 50. The flow resistance through passages 46 and 48 is much lowerthan that through bleed orifice 38, so the pressure within chamber 36drops. This pressure drop creates an opposite force due to pressurewithin passage 32 to raise diaphragm 30 off its seat, as FIG. 1B shows.Diaphragm 30 serves as a pressure-relief valve that lowers the waterpressure within passage 32 (and thus within chamber 25) through aplurality of openings such as opening 51. As a consequence, the biasspring 24 can overcome the force exerted by the pressure within chamber25. The flush-valve member 12 therefore rises, lifting its O-ring seal52 off the main valve seat 14 and thereby allowing the tank to empty asshown in FIG. 1B.

[0052] Importantly, O-ring 52 may be replaced by a rubber or plasticseal having a viper-shaped blade. The viper-shaped blade is designedboth to provide a seal on seat 14 and to clean or remove any depositslocated on the surface of seat 14. The design and the action of theviper-shaped blade further helps in preventing water leaks.

[0053] Gravity flush mechanisms are used with toilets that operate byway of suction created when the rising liquid level in the bowl driveswater to the turn in a vertical conduit bend, where the pull of gravitythen draws fluid down the reverse bend to siphon bowl contents out. Theeffectiveness of the desired suction depends significantly on theprofile of flush-valve movement as the flush valve opens. In the presentembodiments, the flush valves have a repeatable opening-movement profileachieved by employing bias spring 24, which causes the valve-openingmotion. This repeatable motion is then essentially independent of linepressure so long as the pressure-relief path has much less flowresistance than the path by which the chamber is repressurized.

[0054] Referring again to FIG. 1, after tank 16 is emptied, solenoid 42seats valve member 44 to close flow in passages 46 and 48 again. Atleast when the system is battery-operated, it is preferable for thesolenoid to be of the latching variety as described in U.S. Pat. No.6,293,516 (but non-latching solenoid described in U.S. Pat. No.6,305,662 may also be used). That is, it is preferable for the solenoidto require power to change state but not to require power to remain ineither state to increase battery longevity. With valve member 44 seated,the pressure above diaphragm 30 can again build to equal that below it,so diaphragm 30 again seats to cause pressure in chamber 25 to produceenough force to close this main flush valve 12 again. As a result, flowfrom FIG. 1's main line 59 fills the tank through float-valve assembly 5best seen in FIG. 1C.

[0055] Referring to FIG. 1C, float valve assembly 5 uses diaphragm 63 tocontrol water filling tank 16. Specifically, water from line 59 flowsthrough main valve passage 60 formed by a valve cap 61 sealingly securedin a float-valve frame 62. Fill-valve diaphragm 63 is held between valvecap 61 and a valve plug 64 threadedly secured to the valve cap 61 andalso sealed to the float-valve frame 62. At rest, resilient diaphragm 63seats against a valve seat 65 that valve cap 61 forms. Float valveassembly 5 also includes a ball float 66 freely floating in a float cage67. So long as ball float 66 does not plug a pressure-relief orifice 68,the pressure within passage 60 causes such a deformation of theresilient diaphragm 63 as to leave a clearance between it and the valveseat 65. Thus, water from a passage 60 can flow around the valve seat 65through a valve-cap opening 69 and openings 70 in the float-valve frame62.

[0056] The height of pressure relief orifice 68 is designed (orselected) to close the fill valve at a predefined water level. Theresultant rising water in tank 16 eventually lifts float 66 into aposition in which it blocks pressure-relief orifice 68. This preventsthe escape of water that has bled through a high-flow-resistance orifice71 into a chamber 72 formed by diaphragm 63 with valve plug 64. Thus,the pressure within that chamber approaches that within passage 60.Moreover, that pressure acts on the diaphragm 63's lower surface over agreater area than the same pressure does on the diaphragm's uppersurface. The resultant upward force presses diaphragm 63 against itsseat 65 and prevents further flow from the high-pressure line 59 intothe tank. In the illustrated embodiment, the water level at which thisoccurs can be adjusted by adjusting the height within frame 62 of cap61, plug 64, and parts connected to them.

[0057] A user can trigger a solenoid cycle manually by, for instance,using a push button. Alternatively, the solenoid operates automaticallyin response to sensed user activity. For instance, a control circuit 84mounted in a water-tight enclosure 86 and powered by batteries 88provides the solenoid drive current. To determine when to drive thesolenoid, control circuit 84 generates and transmits infrared lightthrough optic fibers 90 to a lens 92 and thereby irradiates a targetregion. Another lens 94 collects light that a target has reflected, andoptic fibers 96 conduct that light to a detector in control circuit 84.Typically, control circuit 84 assumes an “armed” state when a target isdetected. From that armed state, the subsequent absence of a targetwill, possibly after some delay, result in the solenoid's causing theflush valve to open and close in the manner described above.

[0058]FIG. 1D illustrates an embodiment of a tank type flusher having asolenoid control circuitry mounted on the tank. For example, anelectronics enclosure 98 may be mounted on the tank wall, above thetank's high-water line. Lenses 100 and 102 have the same functions asthose shown in FIG. 1's. In the FIG. 1 arrangement, the object-sensorlenses are disposed at the tank's exterior; all of the control circuitryis disposed inside the tank and inside a water-tight enclosure disposedbelow the tank's high-water level. Lenses 92 and 94 can be mounted inthe same enclosure as control circuitry 104 so there is no need foroptic fibers to connect the lenses to the control circuitry. However,the control circuitry is now remote from solenoid 42, which remains inthe watertight enclosure 86. Operator wires 106 lead from controlcircuit 104 to solenoid 42 to enable the control circuit to operatesolenoid 42.

[0059] An alternative, wireless approach would be a hybrid of theapproaches that FIGS. 1 and 1D illustrate. Push-button or sensingcircuitry in such an approach would be located remotely, as in FIG. 1D,but the solenoid-drive circuitry would be local, as in FIG. 1. Theremote circuitry would additionally include a wireless transmitter, andthe local circuitry would include a wireless receiver responsive to thetransmitter. For example, the transmitter and receiver may communicateby way of low-frequency—say, 125 kHz—electromagnetic waves. Suchelectro-magnetic waves may be modulated by pulse trains so encoded as tominimize the effects of spurious reception from other sources. It may bepreferable in wireless approaches for at least the local receiver to belocated above the water line, but this is not required.

[0060] Whereas the FIG. 1D arrangement employs the operator wires 106 tocouple the remote control elements to the local ones, FIGS. 2 and 2Aillustrate an arrangement in which diaphragm 30 is controlled by ahydraulic line 108 (or a pneumatic line). In the embodiment of FIG. 2A,the passage 46 by which the pilot valve's upper chamber 36 is relievedcommunicates through an appropriate fitting 110 with the hydraulic line108. Another fitting 112 on a control-circuit housing 114 places thehydraulic line 108 into communication with a valve passage 116 throughwhich a solenoid 118 controls the flow.

[0061] In one state, solenoid 42 holds a valve member 120 in theposition in which it prevents flow from passage 116 to a further passage122. The pressure in the pilot valve's upper chamber 36 would otherwisebe exhausted to the tank interior by way of an exhaust hose 124 securedto another fitting 126 on the control-circuit housing 114. Exhaust hose124 is provided for those installations in which the control-circuithousing 114 is disposed outside the tank; such installations would needan exhaust hose to return water to the tank. If the housing 114 isinstead mounted inside the tank (above the high-water line), such anexhaust hose is unnecessary.

[0062] In the embodiment of FIG. 1 float-valve assembly 5 is providedseparately from flush-valve assembly 10. Alternatively, the embodimentof FIG. 2 has the float- and flush-valve assemblies located in a singleunit. Frame 130 is mounted on the float-valve pilot assembly just aswatertight enclosure 86 of FIG. 1. Hydraulic line 108 providescommunication with the remote elements, so frame 130 does not need toprovide watertight protection to any local elements. Frame 130 servesthe same function as FIG. 1C's float-valve frame 62. In otherembodiments where it is necessary to protect local elements from waterin the tank, frame 130 can be arranged to provide watertight protection.

[0063] According to another embodiment, FIG. 3 illustrates apressure-type flusher 135 of the tank variety. Pressure-type flusher 135includes a pressure vessel 136, a flush valve assembly and a fill valveassembly. Pressure vessel 136 is always under pressure introduced frommain pressure line 142. A flush-valve member 140 controls flow fromflush valve outlet 138 into the toilet bowl. Flush-valve member 140 ismoveable within a cylinder 144 supported by fins 146 that extend upwardfrom the base of the pressure vessel 136. A bias spring 148 actingbetween a ledge 150 provided by cylinder 144 and a piston head 152formed by valve member 140 tends to lift valve member 140 off its seat154. The pressure in a chamber 156 formed by cylinder 144 between pistonhead 152 and a cap 158 keeps the flush-valve member 140 in theillustrated position, in which it squeezes an O-ring seal 160 againstthe valve seat 154. Seals 162 on the piston head and 164 on the cap helpto prevent the escape from the chamber 156 of pressurized water that hasbeen introduced into it by way of an input pressure line 166.

[0064] To cause the mechanism to flush, pressure in chamber 156 isrelieved by way of a pressure-relief conduit comprising a pilot-valveinlet passage 168, a pilot-valve outlet chamber 170, guide-tube inletpassage 172, a guide tube 176 secured to the cap 158 by a collar 178that the cap forms, and a bore 180, formed by the flush-valve member140, that receives the guide tube 176. Seals 182 on the guide tubeprevent escape of fluid from chamber 156.

[0065] A pressure-relief valve 184 operates similarly to pilot valvespreviously described to control flow through the pressure-relief conduitjust described. Specifically, fluid from the pilot-valve inlet passage168 is ordinarily prevented by diaphragm 186 from flowing around anannular valve seat 188 though valve-cap openings 190 into thepilot-valve outlet chamber 170. When the pressure-relief mechanism'ssolenoid 192 raises a valve member 194 so as to relieve the pressureabove diaphragm 186 through passages 196 and 198, pressure below thediaphragm 186 lifts it off the valve seat 188 and permits relief ofchamber 156's pressure through the pressure vessel 136's flush opening138. By thus relieving the chamber pressure through the valve memberitself, the illustrated flush mechanism avoids the need for a separatepassage to the pressure-vessel exterior.

[0066] The pressure type flusher of FIG. 3 includes control circuitryfor controlling solenoid 192 located locally. According to anotherembodiment, solenoid 192 may be provided remotely, in a manner similarto that depicted in FIG. 2A. The pressure-relief passage could includeconduits that are similar to FIG. 2A's hoses 108 and 124 but communicatewith the embodiment of FIG. 3 passages 196 and 198.

[0067]FIG. 4 illustrates another embodiment of a gravity-typeflush-valve system 200. Similarly as shown in FIGS. 1A and 1B,gravity-type flush valve system 200 includes flush valve member 12seated in flush-valve seat 14 formed in the bottom of toilet tank 16. Inthe seated position, the valve member 12 prevents water in tank 16 thathas entered through flush ports 18 in flush-valve housing 20 fromflowing through flush outlet 21 and flush conduit 22 to a toilet.

[0068] As FIG. 4A shows, the flush mechanism includes bias spring 24.Bias spring 24 exerts a force that tends to urge flush-valve member 12off its seat 14. But pressure that normally prevails in chamber 25because of its communication with pressurized-water source conduit 26keeps the flush-valve member seated between flushes. The flush-valvehousing 20's cap 27 provides this chamber, and the flush-valve member isslideable within a cylinder 28 that the cap forms.

[0069] The valve member's seal ring 29 cooperates with a pilot-valvediaphragm 30 to prevent escape of the pressurized water from the pistonchamber 25 through a pressure-relief outlet 31 in chamber 25's narrowedpassage portion 32. The pilot-valve diaphragm 30 is resilientlydeformable, so the pressure that prevails within passage 32 would tendto lift it from engagement with the pilot-valve seat 34 if a similarpressure did not prevail within pilot chamber 36 and act on thediaphragm 30 over a greater area. The reason why this pressure prevailswithin chamber 36 is that a small orifice 38 through which pilot-valvepin 40 extends permits water to bleed into it (through a relatively highflow resistance).

[0070] In this embodiment, O-ring 52 may again be replaced by a rubber,polymer or plastic seal having a viper-shaped blade. The viper-shapedblade is designed both to provide a seal on seat 14 and to clean orremove any deposits located on the surface of seat 14. The design andthe action of the viper-shaped blade further helps in preventing waterleaks.

[0071] To cause the system to flush, the user depresses FIG. 4's pushbutton 202. As will be explained in more detail below, this causes aremote pressure-relief valve 204 to permit flow to its outlet 206 from apressure-relief tube 208 that communicates with pilot chamber 36 throughpassages 49 (FIG. 4A). This relieves pressure in chamber 36. The flowresistance through that path is much lower than the bleed orifice 38'sflow resistance, so the pressure within chamber 36 drops and permitsthat within passage 32 to raise diaphragm 30 off its seat, as FIG. 4Bshows. Diaphragm 30 serves as a pressure-relief valve. Specifically, itpermits the pressure within the passage 32 and thus within chamber 25 tobe relieved through a plurality of openings such as opening 53. As aconsequence, bias spring 24 can overcome the force exerted by thepressure within chamber 25. Flush-valve member 12 (FIG. 4) thereforerises, lifting its O-ring seal 52 off the main valve seat 14 and therebyallowing the tank to empty.

[0072] After the tank empties, remote valve 44 closes, as will beexplained below in more detail, to prevent any further flow out ofchamber 36. The pressure above diaphragm 30 can therefore again build toequal that below it, so diaphragm 30 again seats to cause pressure inchamber 25 to produce enough force to close the main flush valve 12again. As a result, flow from main line 59 fills the tank through afloat-valve assembly best seen in FIG. 4. Specifically, as describedabove, water from line 59 flows through main valve passage 60 formed bya valve cap 61 sealingly secured in a float-valve frame 62 (FIG. 1C).

[0073] Referring to FIG. 1C, at rest, resilient diaphragm 63 seatsagainst a valve seat 65 that the valve cap 61 forms. At low water level,the pressure within passage 60 causes such a deformation of theresilient diaphragm 63 as to leave a clearance between it and the valveseat 65. Thus, water from passage 60 can flow around the valve seat 65through a valve-cap opening 69 and openings 70 in the float-valve frame62. The rising water in the tank eventually lifts the float 66 into aposition in which it blocks the pressure-relief orifice 68. Thisprevents the escape of water that has bled through ahigh-flow-resistance orifice 71 into a chamber 72 that the diaphragm 63forms with the valve plug 64. Then, the pressure within that chamberapproaches that within the passage 60. Moreover, that pressure acts onthe diaphragm 63's lower surface over a greater area than the samepressure does on the diaphragm's upper surface. The resultant upwardforce presses the diaphragm 63 against its seat 65 and prevents furtherflow from the high-pressure line 59 into the tank.

[0074] Referring to FIG. 5, remote valve 204 includesa movable valvemember 205 actuated by button 202, for releasing pressure in tube 208.The relief tube 208 terminates in a valve inlet 210 and communicateswith a main-valve entrance chamber 212. Cooperating threads on a sealframe 214 and a valve core 216 secure the latter to the former, which inturn is threadedly secured to the housing 220's interior. A net 222threadedly secured to the end of the valve core 216 bears against awasher 218 that holds a screen 224 in place. By flowing through thescreen, water from the entrance chamber 212 can enter an annular space232 sealed by an O-ring 234 that seal frame 214 holds in place againsthousing 220's inner surface.

[0075] A lip seal 234 mounted on seal frame 214 acts as a valve seat. Inthe illustrated, closed valve state a movable valve member 205 seatsagainst that lip seal. When the valve is thus closed, a second lip seal102 mounted on the valve member 205 cooperates with lip seal 234 toprevent water from flowing from an outlet-passage entrance chamber 236,with which a core port 238 provides annular space 232 communication,through an annular outlet passage 240 and out the valve outlet port 206.

[0076] The resultant pressure in the outlet-passage entrance chamber 236exerts a force against the lower lip seal 242 that would tend to unseatthe valve member 205, but the valve member remains seated because equalpressure in another, seating-pressure chamber 244 acts over a greaterarea and thereby exerts a greater, countervailing force. Pressureprevails in that seating-pressure chamber because, as FIG. 5Aillustrates, the valve core forms a pin passage 246 in which a flutedcore pin 248 is disposed to form a high-flow-resistance flow path frommain valve entrance chamber 212 through a further screen 250 into theseating-pressure chamber 244. Acting against the core pin's enlargedhead 252, an internal lip 254 retains the core pin.

[0077] The push button 202 is threadedly secured to an actuator rod 256whose stop surface 258 bears against a valve-member shoulder 260 thatacts as a stationary stop. When depressing button 202, the userovercomes the force of bias spring 262 located in a spring recess 264formed by the valve housing 220. Spring 262 exerts return force on acollar 266 formed by the actuator rod.

[0078] When a user manually depresses push button 202, the actuator rod256 bears against valve member 205, and the user overcomes fluid-flowresistance (explained below) and the force from the seating-pressurechamber 244 to displace the valve member 205 downward. This both unseatsthe valve member from the upper lip seal 234 and draws water out of theseating-pressure chamber 244 through passage 212. By unseating thevalve, the user opens communication between the outlet-passage entrancechamber 236 and the outlet passage 240. That is, pressure in thepressure-relief tube is relieved through a valve flow path that includesthe main entrance chamber 212, the annular space 232, core port 238, theannular outlet passage 240, and the main valve outlet port. An O-ringseal 266 mounted in an annular seal groove 268 that the actuator rod 256forms prevents leakage through the spring recess 264.

[0079] Actuator rod 256 and valve member 205 are cooperativelyconstructed and arranged to relieve pressure in tube 208 and cause delayin pressure buildup after actuation. The actuator rod's end shaft 270 isslideable within the valve member's central passage 272, so the biasspring 262 can urge that actuator-rod's stop surface 258 out ofengagement with the valve member 205 when the user releases the pushbutton 202. The user usually releases the push button while most of thewater has yet to drain from the flush tank. Therefore, there is a delayduring which remote valve 204 remains open so that flush valve 205 alsoremains open. In remote valve 204, valve member 205's movement from itsunseated position to its seated position increases the seating-pressurechamber's volume and thus necessitates flow into seating-pressurechamber 244 in order to return its pressure to the value that prevailsat the inlet 210 and thus in the space 236 whose pressure tends to keepthe valve member 205 unseated. However, the flow resistance of thepassage 246 (FIG. 5A) by which that make-up must flow into theseating-pressure chamber 244 is so great that this flow causes asimplified pressure drop for several seconds. As a consequence, theforce on the valve member 205 caused by the pressure within theseating-pressure chamber 244 is not great enough to overcome the forcefrom space 236's pressure, so the valve member 205 remains unseated forthat length of time.

[0080] The precise duration of the delay between the user's release ifthe push button 202 and the valve member's seating—and thus of the flushvalve's closing—depends to a great extent on the difference between theseating-pressure chamber's volumes in the two states. This in turndepends on the travel permitted by the illustrated valve-closed distancebetween the push button 202's stop surface 280 and the housing's end lip282. A setscrew 284 enables installation personnel to adjust thatdistance and thereby the length of time for which the flush valve isopen. Therefore, remote valve 204 can vary flush duration by adjustablyselecting the time flush valve 10 is opened.

[0081]FIGS. 6 and 6A illustrate another embodiment of a gravity typeflush 300 including a fill valve 302 and a flush valve 304 constructedin a unitary structure. Flusher 300 is actuated by actuator 306. Flushvalve 304 includes a bias spring 310 keeps a gravity-type flushmechanism's flush-valve member 312 separated from a flush-valve seat 314formed on the inlet of a flush conduit 316 disposed in the bottom of atoilet tank 318. As FIG. 6A shows in more detail, a lower main housinghalf 320 mounted by struts 322 on the flush conduit 316 forms a pressurechamber 324 above the valve member 312. Pressure chamber 324 includes acylinder 326 within which a piston portion 328 of the valve member 312is slideable. Chamber 324 is ordinarily under pressure because of fluidcommunication that a pressure line 330 provides between it and apressurized-water supply connected to passage 448. When that pressureprevails, it holds the valve member 312 in a seated position.

[0082] Pressure chamber 324's pressure ordinarily prevails because apilot-valve diaphragm 332 secured in housing half 320 by a pilot-valvecap 333 ordinarily cooperates with the valve member's seal ring 334 toprevent escape of pressurized water from the chamber. The pilot-valvediaphragm 332 is resiliently deformable, so the pressure that prevailswithin chamber 324 would tend to lift it from engagement with apilot-valve seat 336 and thus allow pressure relief if a similarpressure did not prevail within a pilot chamber 338 and act on thediaphragm 332 over a greater area. The reason why this pressure prevailswithin the pilot chamber 338 is that a small orifice 340 through which apilot-valve pin 342 formed by cap 333 extends permits water to bleed(through a relatively high flow resistance) into the pilot chamber.Thus, valve member 312 remains in the seated position (not shown)between flushes.

[0083] To cause the system to flush, the user depresses a push button344 (FIG. 6B). As will be explained in more detail below, this causes aremote pressure-relief valve 346 to permit flow to its outlet 348 from apressure-relief tube 350 secured at its other end by a fitting 352 to aplug member 354 mounted on cap 333. This places remote valve 346'soutlet 348 in communication with a plug member 354's interior passage356 (FIG. 2) and thereby with the pilot chamber 338 through passage 358.This relieves pressure in that chamber. The flow resistance of the pathis much lower than that of the bleed orifice 340, by which the pilotvalve's pressure is replenished, so the pressure within chamber 338drops and permits pressure chamber 324's pressure to raise diaphragm 332off its seat.

[0084] Diaphragm 332 permits the pressure within the pressure chamber324 to be relieved through a plurality of openings such as opening 360.As a consequence, the bias spring 310 can overcome the force exerted bythe now-reduced pressure within chamber 324. The flush-valve member 312therefore rises to its open position (FIG. 6A), lifting its O-ring seal362 off the main valve seat 314 and thereby allowing water from the bankto flow out through the flush conduit 316.

[0085] The user typically doesn't keep the push button 344 depressedlong enough for the required flush volume to flow from tank 16 to thetoilet bowl. However, remote valve 346 nonetheless remains open longenough. Referring to FIG. 6B, push button 344 actually is a compoundbutton consisting of outer and inner button members 364 and 366 held ina button frame 368 by a button cap 370. A flexible diaphragm 372 securedto button frame 368 by an actuator-chamber housing 374 biases innerbutton 366 to the illustrated rest position, in which it additionallyholds the outer button member 364 in its rest position.

[0086]FIG. 6C is a top isometric view of inner button member 366co-operatively arranged with outer button member 364, shown in FIG. 6E.Button member 366 includes a central land 376 extending from a generallydisk-shaped layer 378 from which four keys 380 extend radially. Buttonframe 368 (FIG. 6D) forms a set of sixteen partitions 382 extendingradially inward. Those partitions 382 cooperate to define sixteen keyguides, within any four of which keys 380 can slide. The button frame368 also forms stop surfaces 384 at the bases of the key guides thusformed. The stop surfaces 384 in the key guides occupied by the fourkeys at any one time are all arranged at the same level so that theystop all four keys simultaneously. However, different sets of four stopsare disposed at different levels so that placing the keys in differentsets of the key guides results in different amounts of permitted buttontravel.

[0087] Referring again to FIGS. 6C and 6E, each of the four keys 380includes a passage 386 therethrough. Outer button member 364 isgenerally annular but forms four radially extending tabs 388 from whichrespective legs 390 extend. Legs 390 register with passages 84 in asliding arrangement shown in FIG. 6B.

[0088] When the user operates push button 344, he most often pressesagainst outer button member 364 and thereby depressed that member untilits legs 390 reach the respective key guides' stop surfaces. Outerbutton member 364 bears against inner button member 366 (moving it tothe right in FIG. 6B causing it to deform flexible diaphragms 372 fromits illustrated position, to which it is biased. A valve housing 392secured to the actuator-chamber housing 374 holds in place a secondflexible diaphragm 394, which cooperates with diaphragm 372 andactuator-chamber housing 374 to form an actuator chamber. The actuatorchamber is filled with an incompressible fluid, and button member 366'sdeformation of diaphragm 372 forces the fluid through four angularlyspaced openings 396 in a divider wall 398 that the actuator-chamberhousing 374 forms. In flowing through openings 396, the fluid lifts thelip of an umbrella-type check-valve member 400 snap fit in a centraldivider-wall opening.

[0089] Referring still to FIG. 6B, umbrella-type check valve 400 andopenings 396 and 398 are designed for fast expulsion and slow return ofejected fluid. The fluid's motion urges diaphragm 394 against the forceof a bias spring 401 and thereby pushes to the right a valve member 402slidably disposed in a valve channel 404 formed by valve housing 392.Valve member 402 forms two annular recesses in which respective O-ringseals 406 and 408 are disposed, and rightward motion causes O-ring 408to extend into a widened portion 410 of channel 404 and thereby breakthe seal that it had theretofore maintained with the channel wall.Pressure theretofore prevailing in tube 350 is thereby relieved throughchannel 404 and outlet passage 348. When the user depresses only theouter button member 364, the point at which that members' legs 390encounter their respective lands 384 determines how far into the widenedchannel portion 410 valve member 402 extends.

[0090] When the user releases button, flexible diaphragms 372 and 394tend to resume the rest positions to which spring 401 biases them, sothey act to return the valve 346 to its closed state. To resume the restpositions, they must move the actuator chamber's fluid back through thedividing wall 398. But check valve 400 prevents fluid from flowingthrough openings 396, and the only route through the wall that remainsis therefore a bleed orifice 412, which imposes significant flowresistance and therefore a delay between the user's releases of thebutton and valve 346's closure.

[0091] The duration of the delay depends on the amount of diaphragmdeformation that occurred, and this in turn depends on how far buttonmember 364 traveled. The amount of that travel is determined by theselection of the key guides into which that button member's keys 380were placed; different-level stop surfaces 384 result in differentamounts of travel of legs 390 before they encounter those stop surfaces,but the resultant delay is usually at least two seconds.

[0092] The delay imposed as a result of the user's depressing only theouter button member 366 is usually so selected as not to permit the tankto empty completely but still to permit enough flushing flow for mostpurposes. If the user desires a fuller flush, he instead depresses theinner button member 366's land 376 (FIG. 6C). Button member 366 cantravel farther than member 364; it can travel until it keys 380 reachrespective stop surfaces 384. As a consequence, its operation causesmore of the incompressible fluid to flow through the divider wall 398,and it thus requires more of the fluid to return upon the button'srelease before the valve 346 returns to its closed position. More of thetank's contents therefore flow into the toilet bowl to flush it.

[0093]FIGS. 7A and 7B provide an enlarged view of flusher 300. When thewater level in the tank has fallen significantly below a full-tanklevel, a freely floating float 410 (FIG. 7A) permits float valve 412 toopen. That valve is mounted in an upper main-housing half 414 supportedon the lower main-housing half. The main housing is provided in twohalves so that the float-valve assembly 412's height, and thus the levelto which the tank is allowed to fill, can be adjusted by means notshown.

[0094] A main pressure-inlet manifold 416, which feeds the conduit 330by which pressure chamber 324 is pressurized, forms a further outlet418. Through this outlet it feeds a conduit 420 mounted on the uppermain housing half 414 and forming at its lower edge a float-valve seat422. Formed integrally with the conduit 420 is a generally annular mouthportion 424 in which a pilot-chamber base 426 is threadedly secured.That base cooperates with the conduit 420's mouth portion 424 to form afloat-valve pilot chamber 428 and secure within it a resilientlydeformable float-valve diaphragm 430 that tends to seal against thefloat-valve seat 422. However, a bleed orifice in which is disposed apositioning pin 434 formed by the pilot-chamber base 426 permits fluidfrom the conduit 420 to enter the pilot-valve chamber 428. When apilot-valve member 436 is held by the float 410 against the outlet of apressure-relief passage 438, the pressure in the pilot-valve chamber 428can build up to equal the pressure in the conduit 420 and, prevailingover a larger area than the pressure from the conduit 420, hold thefloat-valve diaphragm 430 seated so that it prevents the liquid inconduit 420 from flowing around the float-valve seat 422 throughmouth-portion openings 440 and a port 442 to a tank-fill tube 444.

[0095] Referring still to FIG. 7A, when the tank level is low float 410does not stop pressure-relief passage 438, so pressure in thepilot-valve chamber 428 is relieved faster than it can be restoredthrough the bleed orifice 432. The pressure in conduit 420 thereforeunseats the float-valve diaphragm 430, so water from conduit 420 canflow into the fill tube 444.

[0096] Fill tube 444 is designed for filling the tank, and thetank-filling flow tends to reduce the manifold pressure (i.e. linepressure). Since that pressure is what closes the flush valve,significant tank-filling flow might impair that valve's closingperformance. Therefore, there is a flow restrictor 416 so that when theflush-valve member 312 is in its fully unseated position, water cannotflow at any significant rate from the fill tube 444 into the tank. Flowrestrictor 446 is mounted on the flush-valve member and protrudes intothe fill tube's outlet as to restrict the tube's flow area greatly. Thishas the beneficial effect of maintaining high pressure in the manifold416 and thus the pressure line 430 by which, through bleed orifice 440,the manifold pressure closes the pilot valve and thus imposes on theflush valve the pressure that closes it. In other words, the flowrestrictor ensures that there is enough pressure to close flush valve304 with significant speed. When flush valve 302 does close, it retractsflow restrictor 446 from the fill tube 444 and thereby allows the tankto fill rapidly.

[0097] The flow-restrictor operation just described tends to make theflush valve's operation more predictable in duration than it wouldotherwise be; tank filling does not adversely affect the pressure thatoperates to close the flush valve. However, the pressure from the watersource can vary, and this, too, could result in undesired variations inthe delay between the remote valve's closing and that of the flushvalve. Referring to FIG. 6, flush valve 304 includes a flow-ratecontroller 448 interposed in the flow path by which theflush-valve-closing pressure is supplied. The particular type of flowcontroller 448 is not critical, but FIG. 7B depicts one of thedeformable-ring variety. A flow restrictor 450 disposed in the conduitcooperates with a resiliently deformable ring 452 to restrict the flowarea through which pressurized water must flow to enter the pressurechamber that applies the closing force to the flush valve. If the supplypressure is relatively low, it does not greatly deform the ring, and theresultant flow area is relatively low, it does not greatly deform thering, and the resultant flow area is relatively great: the already-lowpressure is not reduced much in flowing through the restrictor. If thesupply pressure is high, on the other hand, it deforms the ring by agreater amount and thereby restricts the flow area more significantly.So a greater pressure drop from the originally high pressure occurs. Theflow-rate controller therefore reduces the pressure variation that theflush valve would otherwise experience. This reduces variation in thespeed at which the flush valve closes.

[0098] Plumbing installations can experience not only pressure variationbut also total pressure loss. In the absence of the present invention,such a pressure loss would permit the flush valve to open, causing anunintended flush. But a check valve 454 is provided in pressurizerconduit 330 so that the pressure holding the flush valve closes not lostwhen the line pressure is.

[0099]FIG. 8 illustrates another embodiment of a remote actuator usedwith flusher 300. Remote actuator 500 includes a valve 510, whichcontrols flow from its inlet 511 to its outlet 512. The user depresses apush button 513 to open valve 510. The user typically will not keep thebutton depressed long enough for the required flush volume to flow. Butthe valve 510 nonetheless remains open long enough, as will now beexplained.

[0100] In the illustrated embodiment, push button 513 actually is acompound button consisting of outer and inner button members 514 and516. Those button members are disposed within an operator housing 518that includes an outer housing member 520 and an inner housing member522 threadedly secured to it. The outer housing member 520 forms aflange 524 that cooperates with an end cap 526 to secure the valveassembly to some support such as a toilet-tank wall. An actuator frame528 is threadedly secured to the inner operator-housing member 522 andcooperates with it to clamp a flexible diaphragm 530 into position.Flexible diaphragm 530 urges the inner button member 516 upward in FIG.8, but a knee 532 that the outer operator-housing member 520 forms soengages a shoulder 534 formed by the outer button member 514 as toretain the inner button member 522 within the housing.

[0101] A nut 535 that threadedly engages the actuator housing 528secures a valve housing 536 to the actuator housing 528 and therebyclamps into a fixed position an annular lip 538 formed at the end of asecond flexible diaphragm 540. Together with the actuator housing 528,the first and second flexible diaphragms 530 and 540 form an actuatorchamber divided into first and second chamber segments 542 and 544separated by a divider wall 546 that the actuator housing 528 forms.

[0102] The inner and outer button members 516 and 514 are so sized thata user depressing button 513 will ordinarily depress the outer buttonmember unless he takes care to concentrate on the inner member only.When the outer button member 514 is depressed, it in turn presses downon the inner members plate portion 547, and this causes the firstflexible diaphragm 530 to deform in such a manner as to reduce thevolume of the first chamber segment 542. But the actuation chamber thatsegments 542 and 544 form is filled with an incompressible fluid such asdistilled water, and a reduction in the first chamber segment 542'svolume causes the second segment 544's volume to increase. Specifically,the incompressible fluid flows from the first chamber segment 542,through openings 548, past the lips of a flexible check-valve member550, and into the second chamber segment 544. As a result, the secondflexible diaphragm 540 deforms downward: the second chamber segmentgrows in volume.

[0103] This deformation of the second flexible diaphragm 540 occursagainst the force of a compression spring 552, which is disposed withina spring chamber 554 that the second flexible diaphragm 540 cooperateswith the valve housing 536 to form. That spring bears against anactuator head 556 that in turn bears against the second flexiblediaphragm 540 to bias it into the illustrated position. In thatposition, an O-ring 557 mounted on the actuators shaft 558, which isdisposed within a guide 560 that the valve housing 536 forms, keepswater in the inlet 511 from flowing to the outlet 512. A second O-ring562 prevents inlet water from flowing into the spring chamber 554. Thejust-explained downward deformation of the second flexible diaphragm 540in response to a user's pressing the push button moves the lower O-ring557 into an expanded region 564 and thus breaks its seal. This permitsflow from the valve inlet 511 to the valve outlet 512.

[0104] When the user releases the push button, spring 552 causes thesecond flexible diaphragm 540 to return to the illustrated rest state.For that return to occur, the incompressible fluid has to flow back fromthe second chamber segment 544 to the first chamber segment 542.Check-valve member 550 prevents that return flow from occurring throughthe low-flow-resistance path that the relatively large divider-wallopenings 548 provide. Instead, the returning fluid must all flow througha small divider-wall bleed orifice 572, so the return flow is slow,requiring at least two seconds before the actuator shaft 558 can reach aposition in which the lower O-ring re-seals against the guide 560's walland again prevents main valve flow.

[0105] Of course, the actual closure delay depends on the orifice size,the incompressible fluid's viscosity, and the actuation-chamber size.But it additionally depends upon the degree of deformation from whichthe flexible diaphragms need to recover, and this in turn depends on thelength of button travel. When the user pushes the outer button,outer-button legs 574 move downward through plate-portion holes 575until they meet a stop surface provided by an annular stop member 576.The distance from legs 574's rest position to the position of the stopmember 576 thus determines the button travel when the user pushes theouter button member. If the user instead pushes only on the inner buttonmember, though, that button member can travel a little farther, since itdoes not stop until the inner button member's plate portion 547encounters stop member 576. This feature of enabling the user to choosebetween closure delays is of particular utility when the valve controlstoilet flushing; pressing the outer button results in a normal flush,while pressing only on the inner button results in a fuller flush. Inboth cases, it is the stop member 576's position that determines thebutton travel and thus the closure delay.

[0106] Stop member 576's position depends in turn on the valve's inletpressure, as will now be explained. The inner operator-housing member522 and the stop member 576 cooperate with a tension spring 580, whichis secured to them, to form a resiliently expandable stop. The stopdefines an internal stop chamber 582, which O-rings 583 and 584 seal. Acheck valve 585 allows fluid to flow from a pressurizer conduit 586 intochamber 582 from a pressurizer port 587. That port communicates with theinlet 511 by way of the clearance between the actuator shaft 558 and theactuator guide 560's wall. Pressure at the valve inlet 511 thus canpressurize the stop chamber 582. The tension spring 80 tends to urge thestop member 576 toward the inner operator-housing member's lower end andthereby reduce the stop chamber's size. But the force that the inletpressure exerts on the stop member 576 acts against the spring force andthus tends to expand the expandable stop.

[0107] The degree of stop expansion depends on the inlet pressure: thegreater that pressure is, the more the actuator stop expands. Greaterstop expansion results in the button travel's being more limited andthereby in less delay before the main valve closes. This shorter closuredelay tends to compensate for the greater main-valve flow rate that ahigher pressure causes. That is, it reduces pressure-caused variationsin the volume of liquid that a single push-button operation allows topass through the main valve.

[0108] Now, the outlet pressure typically undergoes a sudden reductionwhen the user operates the valve and thus permits flow from the valveinlet 11 through the valve outlet 512. But the pressurizer check valve585, which readily permits fluid flow from the valve outlet 511 throughthe pressurizer conduit 585 to the stop chamber 576 to pressurize it,retards flow through conduit 586 in the other direction. It therebytends to keep the stop expanded to the size that the inlet pressuredictated before the valve was opened. So the stop remains expandedthroughout the duration of a closure delay, i.e., throughout the timewhen the valve is open. The stop chamber pressure will nonethelessadjust to inlet-chamber pressure reductions that occur while the valveis closed, because a bleed slot 588 formed in the valve member 590'sseat permits depressurization over a longer time scale. Otherembodiments may instead provide a bleed passage 591 through the valvemember rather than around it.

[0109] Although, for the sake of simplicity, FIG. 8 depicts the stopmember 576 as providing a single-level stop surface, it may beadvantageous to have it provide several levels of stop surface so that achoice of closure-delay range can be made while the valve is beingassembled or installed. A stop member such as FIG. 8A's stop member 576′may be employed for this purpose. That stop member is provided with agenerally cylindrical extension 594, from which partitions 596 extendradially inward to form key ways 598. FIG. 8B, which is a stop view ofthe valve assembly with its end plate 526 and outer operator-housingmember 520 removed, show that the outer button in such an embodimentforms keys 602 that fit into four key ways spaced by equal angles fromeach other. As FIG. 8C shows, the inner button similarly forms keys 104that fit into those key ways.

[0110]FIG. 8A shows that the different key ways have different-heightstop surfaces 600. The heights repeat so that each key in any set offour key ways spaced by 90° from each other, such as the set that keys604 of FIG. 8C occupy, have the same height. When the button isassembled, the assembler chooses the closure-delay range by selectingthe 1st of four key ways into which he inserts the outer-button andinner-button keys 602 and 604.

[0111] Having described various embodiments and implementations of thepresent invention, it should be apparent to those skilled in therelevant art that the foregoing is illustrative only and not limiting,having been presented by way of example only. There are otherembodiments or elements suitable for the above-described embodiments,described in the above-listed publications, all of which areincorporated by reference as if fully reproduced herein. The functionsof any one element may be carried out in various ways in alternativeembodiments. Also, the functions of several elements may, in alternativeembodiments, be carried out by fewer, or a single, element.

What is claimed is:
 1. A tank-type flusher, comprising: an intake valveconnected to an external water source and constructed to close waterflow to a water storage tank at about a predefined water level in saidwater tank; a diaphragm-operated flush valve constructed to control aflush valve member between a seated state and an unseated state allowingwater discharge from said water tank into a toilet bowl; a diaphragm,separating a flush-valve chamber and a pilot chamber, arranged to sealsaid flush-valve chamber and thereby maintain pressure forcing saidflush valve member to said seated state preventing said water dischargefrom said water storage tank to said toilet bowl; and a pressure controlmechanism constructed and arranged, upon actuation, to reduce pressurein said pilot chamber of said diaphragm-operated flush valve to causedeformation of said diaphragm and thereby reduce pressure in saidflush-valve chamber causing said water discharge.
 2. The tank-typeflusher of claim 1 wherein said intake valve includes a floatconstructed and arranged without any fixed coupling to any valve member.3. The tank-type flusher of claim 1 wherein said intake valve includes afloat which freely floats within a float cage.
 4. The tank-type flusherof claim 1 wherein said intake valve includes a float arranged to floatwithin a float cage and to block a relief orifice at said predefinedwater level.
 5. The tank-type flusher of claim 1 wherein said pressurecontrol mechanism is controlled by a solenoid.
 6. The tank-type flusherof claim 1 wherein said flush valve member is constructed to movelinearly within a flush valve housing.
 7. The tank-type flusher of claim1 wherein said flush-valve chamber is arranged to receive water pressurefrom said external source and being arranged to prevent said waterdischarge utilizing at least a portion of said water pressure.
 8. Atank-type flusher, comprising: an intake valve constructed to closewater flow from an external water source to a water storage tank whenthere is a predefined water level in said water tank, said intake valveincluding a float constructed and arranged to freely float within afloat cage; and a diaphragm-operated flush valve including a flush-valvechamber, said diaphragm-operated flush valve being constructed to openupon actuation to discharge water into a toilet bowl from said watertank.
 9. A tank-type flusher, comprising: an intake valve connected toan external water source and constructed to close water flow to a waterstorage tank at about a predefined water level in said water tank; and aflush valve constructed to control position of a flush valve membermovable between a seated state and an unseated state allowing waterdischarge from said water tank into a toilet bowl; said flush valvemember being biased to said unseated state by a bias member and beingforced to said seated state by at least a portion of water pressure fromsaid external source.
 10. The tank-type flusher of claim 1, 8 or 9wherein said intake valve and said flush valve are located within asingle housing.
 11. The tank-type flusher of claim 9 wherein saidflush-valve chamber is arranged to receive a water pressure from saidexternal source and is arranged to prevent said water dischargeutilizing at least a portion of said water pressure.
 12. The tank-typeflusher of claim 9 wherein said diaphragm-operated flush valve iscontrolled by a solenoid.
 13. The tank-type flusher of any one of theabove claims wherein said water tank is an exposed water tank.
 14. Thetank-type flusher of any one of the above claims wherein said water tankis a concealed water tank located behind a wall.
 15. The tank-typeflusher of any one of the above claims wherein said intake valve enablesa variable water level in said tank.
 16. The tank-type flusher of anyone of the above claims including a vacuum breaker arranged to preventtransfer of water from said tank to a water supply.
 17. The tank-typeflusher of any one of the above claims including a manual actuatorconstructed and arranged to actuate said flush valve.
 18. The tank-typeflusher of claim 17 wherein said manual actuator is a push buttonactuator.
 19. The tank-type flusher of claim 18 wherein said push buttonactuator is constructed to actuate said flush valve enabling a dualwater volume flush.
 20. The tank-type flusher of claim 18 wherein saidpush button actuator is constructed to actuate hydraulically said flushvalve.
 21. The tank-type flusher of any one of the above claimsincluding an automatic actuator constructed and arranged to actuate saidflush valve.
 22. The tank-type flusher of claim 17 wherein saidautomatic actuator is constructed to be triggered by a sensor.
 23. Thetank-type flusher of claim 22 wherein said sensor registers presence ofan object.
 24. The tank-type flusher of claim 22 wherein said sensorregisters movement of an object.
 25. The tank-type flusher of claim 22wherein said sensor is an optical sensor.
 26. The tank-type flusher ofclaim 21 wherein said automatic actuator is constructed to actuate saidflush valve enabling a dual water volume flush.
 27. The tank-typeflusher of claim 21 wherein said automatic actuator is located outsideof said water tank and is constructed to actuate hydraulically saidflush valve.
 28. The tank-type flusher of claim 1, 8 or 9 including acheck valve arranged to reduce variation of closing pressure dependingon water line pressure.
 29. The tank-type flusher of claim 1, 8 or 9including a pressure compensated flow regulator.
 30. The tank-typeflusher of claim 1, 8 or 9 including a viper seal cooperatively arrangedwith said flush valve to prevent water leaking into said toilet bowl.31. The tank-type flusher of claim 1, 8 or 9 including a vent forcontrolling odor
 32. A flusher comprising: a tank forming a flush outletby which liquid in the tank may leave the tank for flushing; aflush-valve member operable between an unseated state, in which itpermits flow from the tank through the flush outlet, and a seated state,in which it prevents flow from the tank therethrough; a valve-operatingmechanism including a housing that defines a control chamber disposed ata local location and forms a line-pressure inlet that admits water linepressure into the control chamber and further forms a control-chamberpressure-relief outlet, by which pressure in the control chamber can berelieved, the valve-operating mechanism operating the flush-valve memberto its seated state when the line pressure prevails in the controlchamber and operating the flush-valve member to its unseated state whenthe pressure in the control chamber is relieved, the valve-operatingmechanism further including: a pressure-relief conduit extending fromthe control-chamber pressure-relief outlet to a remote location andthereby providing a pressure relief path; and a remote valve, disposedat the remote location, interposed in the pressure-relief path, andincluding: a) chamber walls, including first and second displaceablewalls, forming a closed actuator chamber; b) and incompressible fluidthat fills the actuator chamber; c) a remote-valve member coupled to thesecond displaceable wall for displacement therewith between a closedstate, to which it is biased and in which it prevents flow through thepressure-relief conduit and thereby prevents relief of pressure withinthe control chamber, and an open state, in which it permits relief ofpressure within the control chamber; d) a push button displaceable bymanual depression and so coupled to the first displaceable wall as todisplace the first displaceable wall and thereby the incompressiblefluid, the second displaceable wall, and the valve to the open state; e)an actuation-chamber divider that divides the actuator chamber intofirst and second chamber segments in which the first and seconddisplaceable walls are respectively located, the divider providing forasymmetric flow therethrough such that it exhibits such higher flowresistance to flow of the incompressible fluid therethrough from thesecond chamber segment to the first chamber segment than from the firstchamber segment to the second chamber segment as to impose a time delayof at least two seconds between release of the push button and theremote-valve member's closure of the pressure-relief path.
 33. A flusheras defined in claim 32 wherein the actuation-chamber divider includes: adivider wall forming forward and reverse passages therethrough; and acheck valve positioned and oriented to permit flow from the firstchamber segment through the forward passage to the second chambersegment but not from the second chamber segment through the forwardpassage to the first chamber segment; and wherein the incompressiblefluid flows through the reverse passage when the displaceable walls aredisplaced by the remote-valve member's assuming its closed state.
 34. Aflusher comprising: a tank forming a flush outlet by which liquid in thetank may leave the tank for flushing; a flush-valve member operablebetween an unseated state, in which it permits flow from the tan throughthe flush outlet, and a seated state, in which it prevents flow from thetank therethrough; a valve-operating mechanism including a housing thatdefines a control chamber disposed and forms a line-pressure inlet thatadmits water line pressure into the control chamber and further forms acontrol-chamber pressure-relief outlet, by which pressure in the controlchamber can be relieved, the valve-operating mechanism operating theflush-valve member to its seated state when the line pressure prevailsin the control chamber and operating the flush-valve member to itsunseated state when the pressure in the control chamber is relieved; apressurizer conduit having an upstream thereof and a downstream end thereof that so communicates with the control chamber that pressurizedwater applied to the pressurizer conduit at an upstream end thereof canpressurize the control chamber; and a pressure controller interposed inthe pressurizer conduit, the pressurizer conduit imposing a pressuredrop from its upstream to its downstream side that increases anddecreases with upstream pressure.
 35. A flusher comprising: a tankforming a flush outlet by which liquid in the tank may leave the tankfor flushing; a flush-valve member operable between an unseated state,in which it permits flow from the tank through the flush outlet, and aseated state, in which it prevents flow from the tank therethrough; avalve-operating mechanism including a housing that defines a controlchamber disposed and forms a line-pressure inlet that admits water linepressure into the control chamber and further forms a control-chamberpressure-relief outlet, by which pressure in the control chamber can berelieved, the valve-operating mechanism operating the flush-valve memberto its seated state when the line pressure prevails in the controlchamber and operating the flush-valve member to its unseated state whenthe pressure in the control chamber is relieved; a pressurizer conduithaving an upstream thereof and a downstream end thereof that socommunicates with the control chamber that pressurized water applied tothe pressurizer conduit at an upstream end thereof can pressurize thecontrol chamber; and a check valve interposed in the pressurize conduitand oriented to permit flow toward the pressurizer conduit's upstreamendbut not toward its upstream end.
 36. A flusher comprising: a tankforming a flush outlet by which liquid in the tank may leave the tankfor flushing; a flush-valve member operable between an unseated state,in which it permits flow from the tank through the flush outlet, and aseated state, in which it prevents flow from the tank therethrough; avalve-operating mechanism including a housing that defines a controlchamber disposed and forms a line-pressure inlet that admits water linepressure into the control chamber and further forms a control-chamberpressure-relief outlet, by which pressure in the control chamber can berelieved, the valve-operating mechanism operating the flush-valve memberto its seated state when the line pressure prevails in the controlchamber and operating the flush-valve member to its unseated state whenthe pressure in the control chamber is relieved; a manifold having aninlet and pressurizer and fill outlets; a pressurizer conduit having anupstream thereof in fluid communication with the pressurizer outlet anda downstream end thereof that so communicates with the control chamberthat pressurized water applied to the pressurizer conduit at an upstreamend thereof can pressurize the control chamber; a fill conduit having anupstream thereof in fluid communication with the fill outlet and adownstream end t hereof from which the tank can be filled; and a flowdiverter so mounted on the flush-valve member as to extend into thedownstream end of the pressurizer conduit as to restrict the flow areatherethrough when the flush valve is in its unseated state but leave agreater flow area when the flush valve is in its seated state.
 37. Apressure-responsive valve system comprising: a delayed-closure valveforming a valve outlet and a valve inlet through which fluid can beintroduced into the valve at an inlet pressure, the delayed-closurevalve being operable from a closed state, in which the delayed-closurevalve prevents flow therethrough from the valve inlet to the valveoutlet, through a range of open states, in which it permits such flow,the delayed-closure valve being so biased that, after release from agiven open state, it returns to the closed state after a closure delaythat varies with how far the given state is into the range of openstates: a valve operator biased to a retracted position, in which itpermits the delayed-closure valve to remain in its closed position, andmanually operable through a range of extended positions, in each ofwhich it holds the valve in corresponding open states within the rangethereof; an operator stop forming a stop pressure chamber and beingresiliently expandable by pressurization of the stop pressure chamber,the operator stop being positioned to reduce the range of the valveoperator's extended positions as the operator stop expands; and apressurizer conduit so extending from the valve inlet to the stoppressure chamber that the stop pressure chamber receives the inletpressure, whereby the closure delay decreases with increases in inletpressure.
 38. A pressure-responsive valve system as defined by claim 37further including a check valve so interposed in the pressurizer conduitas to permit fluid flow from the valve inlet toward the stop pressurechamber but retard flow from the stop pressure chamber toward the valveinlet.
 39. A pressure-responsive valve system as defined by claim 38wherein the valve system forms a bleed orifice that permits flow fromthe stop pressure chamber toward the valve inlet with a flow resistancegreater than that with which the check valve permits flow from the valveinlet toward the stop pressure chamber.
 40. A pressure-responsive valvesystem as defined by claim 39 wherein: the check valve includes acheck-valve member resiliently biased toward a valve seat, from whichflow from the valve inlet toward the stop pressure chamber tends tounseat it; and the check-valve member forms the bleed passagetherethrough.
 41. A pressure-responsive valve system as defined by claim37 wherein the operator stop includes a stop base and a stop member,positioned to stop the valve operator, that cooperates with the stopbase to define the stop chamber and is resiliently displaceable withrespect thereto to provide the resilient expansion of the operator stop.42. A pressure-responsive valve system as defined by claim 41 whereinthe operator stop further includes a stop spring that biases the stopmember against displacement that expands the operator stop.
 43. Apressure-responsive valve system as defined by claim 42 wherein thespring is a tension spring acting between the stop member and the stopbase.
 44. A pressure-responsive valve system as defined by claim 43further including a check valve so interposed in t he pressurizerconduit as to permit fluid flow from the valve inlet toward the stoppressure chamber but retard flow from the stop pressure chamber towardthe valve inlet.
 45. A pressure-responsive valve system as defined byclaim 44 wherein the valve system forms a bleed orifice that permitsflow from the stop pressure chamber toward the valve inlet with a flowresistance greater than that with which the check valve permits flowfrom the valve inlet toward the stop pressure chamber.
 46. Apressure-responsive valve system as defined by claim 37 wherein thedelayed-closure valve includes: a valve seat surrounding the valveinlet; a valve operator; chamber walls, including first and seconddisplaceable walls, forming a closed actuator chamber, the firstdisplaceable wall being coupled to the valve operator for displacementthereby; an incompressible fluid that fills the actuator chamber,whereby displacement of the first displaceable wall by the valveoperator results in displacement of the second displaceable wall; avalve member coupled to the second displaceable wall for displacementtherewith between a closed state, to which it is biased and in which itso seats in the valve seat as to prevent flow from the valve inlet tothe valve outlet, and an open state, in which it permits such flow; andan actuation-chamber divider that divides the actuator chamber intofirst and second chamber segments in which the first and seconddisplaceable walls are respectively located, the divider providing suchhigher flow resistance to flow of the incompressible fluid therethroughfrom the second chamber segment to the first chamber segment than fromthe first chamber segment to the second chamber segment as, when thevalve operator has been held in a position in which the operator stopstops it, to impose a time delay of at least two seconds between releaseof the valve operator and closure of the valve.
 47. Apressure-responsive valve system as defined by claim 46 wherein theactuation-chamber divider includes a check valve positioned and orientedto permit flow from the first chamber segment to the second chambersegment but retard flow from the second chamber segment to the firstchamber segment.
 48. A pressure-responsive valve system as defined byclaim 47 wherein the actuation-chamber divider includes a divider wallforming forward and reverse passages therethrough; and wherein the checkvalve is positioned and oriented to permit flow from the first chambersegment to the second chamber segment through the forward and reversepassages both; and arranged to permit flow from the second chambersegment to the first chamber segment through the reverse passage but notthrough the forward passage.
 49. A pressure-responsive valve system asdefined by claim 46 further including a check valve so interposed in thepressurizer conduit as to permit fluid flow from the valve inlet towardthe stop pressure chamber but retard flow from the stop pressure chambertoward the valve inlet.
 50. A pressure-responsive valve system asdefined by claim 48 wherein the valve system forms a bleed orifice thatpermits flow from the stop pressure chamber toward the valve inlet witha flow resistance greater than that with which the check valve permitsflow from the valve inlet toward the stop pressure chamber.
 51. Aflusher comprising: tank forming a flush outlet by which liquid in thetank may leave the tank for flushing; flush-valve member biased to anunseated state, in which it permits flow from the tank through the flushoutlet, and operable between its unseated state and a seated state, inwhich it prevents flow from the tank therethrough; flush-valve housingthat forms a flush-valve chamber in which at least a portion of theflush-valve member is movably disposed, the flush-valve housing furtherforming a flush-valve chamber pressure-relief outlet and a line-pressureinlet that so admits water line pressure into the flush-valve chamber asto keep the valve in its seated state when water line pressure above aminimum hold pressure prevails in the flush-valve chamber; andpressure-relief mechanism operable between a closed state, in which itprevents relief of flush-valve-chamber pressure through the flush-valvechamber pressure-relief outlet, and an open state, in which it relievesflush-valve-chamber pressure through the flush-valve chamberpressure-relief outlet.
 52. A flusher as defined in claim 51 wherein thepressure-relief mechanism includes a pressure-relief conduit extendingbetween a remote location and a local location, at which the flush-valvechamber is disposed; wherein the pressure-relief mechanism so operatesas to permit relief of flush-valve chamber pressure through theflush-valve chamber pressure-relief outlet when flow through thepressure-relief conduit is permitted and to prevent relief offlush-valve chamber pressure through the flush-valve chamberpressure-relief outlet when flow through the pressure-relief conduit isprevented; and wherein the pressure-relief mechanism further includes aremote valve disposed at a remote location, interposed in thepressure-relief conduit, and operable between a closed state, in whichit prevents flow through pressure-relief conduit, and an open state, inwhich it permits flow through the pressure-relief conduit.
 53. A flusheras defined in claim 52 wherein the flush mechanism further includes aliquid-level controller that fills the tank to a target liquid level;wherein the flush-valve chamber is disposed in the portion of the tankinterior that is below the target liquid level; and wherein the remotevalve is disposed outside the portion of the tank interior that is belowthe target liquid level.
 54. A flusher as defined in claim 51 whereinthe pressure-relief mechanism further includes an object sensor, whichgenerates an object-sensor output; and wherein the pressure-reliefmechanism operates between its open and closed states in accordance withthe object-sensor output.
 55. A flusher as defined in claim 4 whereinthe object sensor includes: a fiber-optic cable that extends between alocal location and a remote location; a sensor lens so disposed at theremote location as to focus light from a target region into thefiber-optic cable; and a sensor circuit, disposed at the local location,that generates an object sensor output in accordance with light receivedfrom the fiber-optic cable.
 56. A flusher as defined in any one ofclaims 51 though 55 wherein the flush mechanism further includes aliquid-level controller that fills the tank to a target liquid level;wherein the remote location is outside the portion of the tank interiorthat is below the target liquid level; the local location is inside theportion of the tank interior that is below the target liquid level. 57.A flusher as defined in any one of claims 51 though 55 wherein thepressure-relief mechanism includes a latching solenoid and assumes itsclosed state when the latching solenoid is in one of its stable statesand assumes its open state when the latching solenoid is in the other ofits stable states.
 58. A flusher as defined in claim 57 wherein thepressure-relief mechanism is battery-powered.
 59. A flusher as definedin any one of claims 51 though 55 wherein the pressure-relief mechanismis battery-powered.
 60. A flusher comprising: a pressure vessel forminga flush outlet by which liquid in the vessel may leave the pressurevessel for flushing; a flush-valve member biased to an unseated state,in which it permits flow from the pressure vessel through the flushoutlet, and operable between its unseated state and a seated state, inwhich it prevents flow from the pressure vessel therethrough; aflush-valve housing that forms a flush-valve chamber in which at least aportion of the flush-valve member is movably disposed, the flush-valveenclosure further forming a line-pressure inlet that so admits waterline pressure into the flush-valve chamber as to keep the valve in itsseated state when water line pressure above a minimum hold pressureprevails in the flush-valve chamber; a pressure-relief passage extendingfrom the flush-valve-chamber interior through the valve member to theflush outlet; and a pressure-relief mechanism operable between a closedstate, in which it prevents relief of flush-valve-chamber pressurethrough the pressure-relief passage, and an open state, in which itrelieves flush-valve-chamber pressure through the pressure-reliefpassage.
 61. A flusher comprising: a tank forming a flush outlet bywhich liquid in the tank may leave the tank for flushing; a flush-valvemember operable between an unseated state, in which it permits flow fromthe tank through the flush outlet, and a seated state, in which itprevents flow from the tank therethrough; and a valve-operatingmechanism including a housing that defines a control chamber disposed ata local location and forms a line-pressure inlet that admits water linepressure into the control chamber and further forms a control-chamber topressure-relief outlet, by which pressure in the control chamber can berelieved, the valve-operating mechanism operating the flush-valve memberto one of said seated and unseated states thereof when the line pressureprevails in the control chamber and operating the flush-valve member tothe other of said seated and unseated states thereof when the pressurein the control chamber is relieved.